Growth supplements, biologically active agents such as hormones and growth factors, and antibiotics have been used in animal diets to improve yields and carcass conditioning. As the demand for protein increases in the world, animal producers require improved feeds and feed supplements to assist in output of intensive livestock farming practices.
Ractopamine hydrochloride (RAC, Paylean™, Elanco Animal Health, Greenfield, Ind.)) is a beta adrenergic agonist (β-agonist) that is approved for use as an in feed ingredient for pigs. RAC is a widely used pig feed ingredient, approved for use in most major pork-producing countries, that directs nutrients to increase the amount of lean pork while maintaining meat quality. RAC has been widely demonstrated to improve feed efficiency and growth rates both in Australia (Dunshea et al. 1993 Journal of Animal Science 71: 2931-2941; Smits and Cadogan, 2003 Recent Advances in Animal Nutrition in Australia, Volume 14, Ed J. L. Corbett, Page 143-150) and overseas (Watkins et al. 1990 Journal of Animal Science, 68:3588-3595). RAC is a growth promoter but also keeps pigs leaner.
The present inventors have developed an improved animal feed supplement and methods to improve feed efficiency of animals.